Field of the Invention
The present invention relates to a restoration filter generation device and method that generate a restoration filter to perform restoration processing on luminance system image data generated on the basis of the image data of each color of multiple colors, an image processing device and method that perform restoration processing using this restoration filter, an image capturing apparatus including this image processing device, a program to generate a restoration filter, and a recording medium.
Description of the Related Art
In an image obtained by imaging an object by an image capturing apparatus such as a digital camera, there is a case where image degradation that originates in various aberrations of an optical system (such as an imaging lens) occurs. This image degradation by aberration can be expressed by a PSF (Point Spread Function), or the like. Therefore, the image degradation can be reduced by generating a restoration filter on the basis of the deterioration characteristic of an optical system such as the PSF and performing point image restoration processing (restoration processing) on image data by using this restoration filter.
Japanese Patent Application Laid-Open No. 2010-140442 (hereinafter referred to as PTL 1; especially, see paragraphs [0043] to [0048]) discloses an invention that separates luminance component Y from image data input from an image capturing device, acquires point spread function PSFy (=Wr×PSFr+Wg×PSFg+Wb×PSFb) of the luminance component by synthesizing point spread functions (PSFr, PSFg, PSFb) of respective colors of R, G and B by using coefficients (Wr, Wg, Wb) of R, G and B in the luminance component Y (=Wr×R+Wg×G+Wb×B), and calculates a correction coefficient with respect to luminance component Y on the basis of point spread function PSFy of this luminance component.
Japanese Patent Application Laid-Open No. 2011-193277 (hereinafter referred to as PTL 2) discloses an invention that changes the gain of a restoration filter (amplitude characteristic) according to the amount of adjustment with an adjustment bar by the user in a case where the amplitude characteristic is selected as an adjustment parameter of the restoration filter, and changes the phase angle (phase characteristic) of the restoration filter according to the amount of adjustment with the adjustment bar by the user in a case where the phase characteristic is selected as an adjustment parameter.
Japanese Patent Application Laid-Open No. 2012-129932 (hereinafter referred to as PTL 3) discloses an invention that reduces a difference (chromatic aberration) between color components of a point spread function by relative parallel displacement and generates a restoration filter on the basis of the point spread function.